Document Type : Original Articles


1 Department of exercise Physiology and Corrective exercise, Faculty of Sport Sciences, Urmia University, Urmia, Iran.

2 Department of Exercise physiology and corrective exercises,Faculty of Physical Education and Sport Sciences, Urmia University, Urmia, Iran



Background: The aim of this study was to investigate the effect of volleyball specific fatigue on balance, proprioception and performance of volleyball players with high and low risk of ACL injury.
Methods: The current research was a semi-experimental type with a pre-test-post-test design. therefore, 40 volleyball players from Urmia were selected in two groups with low and high risk of ACL injury. After selecting the subjects by using landing error scoring system (LESS) test (score below 6 indicates low risk and score above 6 indicates high risk), static balance with stork test, dynamic balance with Y balance test, knee proprioception with goniometer and performance with Sargent jump test was evaluated. After that, the special volleyball fatigue protocol was used to create fatigue and after causing fatigue, the tests were evaluated again. Analysis of covariance and dependent t-tests were used to compare the differences inter-group and intra-group.
Results: The results of dependent t-tests and analysis of covariance showed that fatigue had a significant effect on the reducing of static balance (P=0.001, P=0.001), the total score of dynamic balance (P=0.001, P=0.001) and It has performance (P=0.001, P=0.001). The results of Wilcoxon and U-Man-Whitney tests also showed that fatigue has a significant effect on reducing proprioception (P=0.001, P=0.001). The results also showed a significant difference between the groups in all variables (P<0.05) except proprioception (P>0.05).
Conclusion: In general, the results of the present study showed that fatigue was an important factor in reducing balance, proprioception and explosive power, that this decrease in the group with high risk of injury is more than the group with low risk of injury and this difference can be attributed to the basic neuromuscular weakness in the high-risk group of injury.